If you are buying for a skater and need a little help understanding the skate terms on this site, our footnotes are your friend.Skateboarding bearings are small metal rings that contain round balls packed in grease that are inserted into your wheels (tapped in lightly) before your wheels are mounted onto the axle of your truck. Skate bearings usually carry an ABEC rating to show quality however, many competition grade bearings do not have an ABEC class since they perform better than the standards designated by the ABEC commission. The better the bearing, the faster the board will go on either street or ramp conditions. Thank you for shopping for at ClassicBoardco Skateboards